reeber etal



Jan. 21, 1964 R. REEBER ETAL 3,113,404

STITCHING PATTERN SELECTOR ASSEMBLY FOR ZIGZAG SEWING MACHINES Filed March 9, 1962 2 Sheets-Sheet l mum/raps Panama-555p FEM/flaw Dam/5,?

Jan. 21, 1964 R. REEBER ETAL 3,113,404

STITCHING PATTERN SELECTOR ASSEMBLY FOR ZIGZAG SEWING MACHINES Filed March 9, 1962 2 Sheets-Sheet 2' AmJP/wy United States Patent Ofiice 3d ldfid 'l Patented Jan. 21, 1964 3,113,404 STKTQHENG PATTERN SELECTQR ASEMBLY Ftlll Zl'GZAG SEW ENG MAQHINES Rudolf lleeber and Reinhold Dobner, Kaiserslautern,

lfalz, Germany, assignors to G. Pfalf AG, Kaiser'slantern, Pfalz, Germany, a corporation of Germany Filed Mar. 9, 1962, Ser. No. 178,752 Qlaims priority, application Germany Mar. 14, 1961 ll Claims. (Ql. 1l2l58) The present invention relates to zigzag sewing machines, more particularly to improved means or control devices for selectively sewing a plurality of stitching patterns or designs, such as for use in connection with decorative and the like stitching operations.

More specifically, the invention is concerned with an improved stitching pattern selector assembly of the general type suitable for combination with conventional zig zag sewing machine constructions, wherein the oscillating movements of the needle bar or equivalent oscillating stitch-forming organ of the machine are controlled by means of a plurality of control cams or disks in cooperation with cam followers or feeler elements forming part of an oscillating motion-transmitting linkage or mechanism.

The construction of the conventional stitching pattern control devices utilizing cam disks as stitching pattern control means involves principally the provision of at least two rotary axes for the production of the oscillating control impulses to be applied to the needle bar, work feed dog, or the like oscillating organ of a zigzag sewing machine, it being customary to arrange said axes one parallel to the other. One of said axes coincides with the axis of the disk assembly or stack, while the other axis coincides with the axis of the rocking or oscillation-transmitting member fitted with one or more cam followers or eelers at one end for cooperation with said disks and having its opposite ends operatively connected with the oscillating control organ of the sewing machine (needle bar, work feed dog) through suitable motion-transmitting linkage or mechanism.

As a consequence, the known stitching pattern control devices, involving the provision of at least two rotary axes or operating shafts mounted upon a base plate or support, have the disadvantage and drawback of being both bulky and requiring considerable mounting space, a defect especially felt where the pattern control devices are to be embodied in or attached as auxiliary units to existing sewing machine constructions. These difficulties may be multiplied manyfold in such cases where the pattern control device is designed to enable the carrying out of plural control operations, either separately or simultane ously, by means of a single cam or control disk assembly. As an example, it may be desirable or required to control the stitch position, the overstitch width and the work feed advance or stroke in connection with a singly decorative or the like sewing operation. in such a case, four in place of two rotary axes or drive shafts will be required, to wit one for the stack of control disks, and one each for the three oscillation-transmitting members connected with the needle bar and work feed control, respectively.

Moreover, the known devices by involving the use of relatively large sliding surfaces or parts, are both subject to rapid wear and sensitive to outside forces or influences, inasmuch as the parts must be adjusted or aligned accurately to result in clear-cut or well-defined stitching patterns. As a consequence, misalignments 0r displacements due to mechanical vibrations or the like forces and influences have been found to occur frequently both during installation and operation of the stitching control devices .eretofore'known and used in the art.

Accordingly, an important object of the present invention is the provision of improved stitching pattern selector and control mechanism which is substantially free from the foregoing and related defects and difficulties and which may be fabricated readily either as a separate attachment to or for direct structural embodiment in con ventional zigzag sewing machines.

Among the more specific objects of the invention are the provision of stitching pattern control means of the type referred to which is both compact in construction and insensitive to outside forces or influences; which is substantially free from relatively large sliding surfaces or parts liable to result in excessive friction and requiring frequent readjustments or replacements; which can be readily adapted for the production of a plurality of independent oscillating movements or drives derived from a single control cam assembly; and which is both simple in design and economical in manufacture, as well as efiicient and reliable in use or operation.

The invention, both as to its ancillary objects and novel aspects, will be better understood from the following detailed description, taken in conjunction with the accompanying drawings forming part of this specification and wherein:

FIG. 1 is a perspective view of a stitching pattern selector assembly constructed in accordance with the principles of the invention and being partly broken away, the position illustrated corresponding to the non-use or rest position of the device;

FIG. 2 is a view similar to FIG. 1 with the control knob of the device being shown separately and with the parts illustrated in the operative position for the sewing of one of the plural decorative stitching patterns stored in the control cam assembly;

FIG. 3 is a partial showing of the motion-transmitting rocking member of FIGS. 1 and 2, connecting the control cams with the oscillating organ (needle bar, work feed dog) of the sewing machine;

FIG. 4 shows a modified construction of the rocking member forming part of the motion-transmitting mechanism, to provide two simultaneous oscillating drives or controls governed by a single cam assembly; and

H6. 5, being similar to FIG. 4 illustrates another construction of the rocking member for the production of res drives or controls operated by a single cam assembly.

Like reference numerals denote like parts in the different views of the drawings.

With the foregoing objects in View, the invention involves generally the provision of an improved stitching pattern selector for zigzag sewing machines which can be readily embodied in conventional sewing machine constructions and which is substantially insensitive to outside forces and influences by the elimination or minimizing of relatively large sliding surfaces or parts. These aims and other desi able advantages as pointed out herein are achieved principally, in accordance with the underlying concept and novel principle of the invention, by an improved construction, wherein the oscillating axis of the motion-transmitting rocking member or members being controlled by the cam disks coincides with the rotating axis of the cam disk assembly, in such a manner as to result both in a compact structure and in the practical elimination of relatively large sliding surfaces or parts and, in turn, in the minimizing of both mounting space and bulk of the control device, as will become further apparent as the description proceeds.

According to a preferred embodiment of the invention, the motion-transmitting rocking member takes the form of a ring concentrically encircling the rotatably mounted stack or cam disk assembly, said ring being, in turn, mounted for rotative oscillatory movement in a corresponding annular groove of a base plate or support of the device and having a radial extension adapted for operative connection with a stitch-forming organ(needle bar, work feed dog) for the production of zigzag stitching by the sewing machine, in a manner well known and unerstood by those skilled in the art. In order to altord a selection of a plurality of stitching patterns, said ring is fitted with a plurality of actuating elements, such as pins, being equal in number to the number of control cams or disks and projecting to varying heights from said ring dillering from each other by the thickness of the coordinated control disks. In this manner, the e is obtained an extremely compact structure or mechanism enabling a selective control of a plurality of stitching patterns according to the number of cam disks provided, in a manner as will be further understood from the following.

More particularly, there are provided for this purpose a number of actuating or cam follower levers secured to bolts uniformly singularly disposed etween the cam disk assembly and said ring, said bolts being mounted in the base plate or support for both rotation and axial displacement by a distance equal to the thickness of the coordinated cam disks. One arm of said levers forms a cam follower or fceler adapted for cooperation with the contour surface of the coordinated cam disk, while the opposite lever arms are arranged to engage the coordinated actuating pins of said ring during the axial displacement of the levers by means of a suitable control knob or the like operating member for selecting a desired stitching pattern.

The advantages of a selector device of this type, aside from the substantial reduction of size and bulk, are predicated mainly on the fact that the operation involves principally relatively small oscillating or rotary motions only, whereby to reduce wear due to friction and other defects and to render the device substantially insensitive to vibrational forces and other outside influences, compared with the stitching pattern selector assemblies heretofore used in the prior art.

If desirable, the annular rocking member may be divided into two or more concentric sections or segments each being arranged for cooperation with different cam disks or groups of disks of a single stack or cam assembly and serving to provide independent oscillating drives or the control of different operating organs of the sewing machine, such as, for example, for effecting a simultaneous or coordinated control of the overstitch width, of the mean stitch position, of the length of the work feed advance or stroke, as well as of other operations that may be required for the production of a desired zigzag stitching pattern or design.

Referring more particularly to FIGS. 1 to 3 of the drawings, the numeral 1 designates a base plate or support being provided with a circular groove 2 wherein is mounted for rotative oscillatory movement a fiat annular member or ring 5 having a radial extension or arm 4, to form a motion-transmitting rocking member, said arm being subject to the action of a return spring 3 and adapted for operative connection to a stitch-forming oscillating organ (needle bar, work feed dog) of a sewing machine through a further link or connecting arm 4', to produce zigzag stitches in a manner well known and understood by those skilled in the art.

Further rotatably mounted upon the plate 1 concentrieally with the groove 2 or ring 5 is a stack or assembly of control or cam disks 6, H6. 2, having a common rotating axis and each presenting a surface or contour designed for the production of a different stitching pattern, said stack being arranged for rotation by the arm shaft of the sewing machine, as is customary with zigzag pattern control devices of this type. Furthermore mounted upon the plate 1 between the stack 6 and the ring 5 and at equal distances from the axis of rotation of said stack are a plurality of double-arm actuating or follower levers 9 each comprising a pin or bolt 7 displaceable in the axial direction against the action of a coil spring 8 encircling the lower ends of the LS and having one end engaging a bore in the plate 1 and having their opposite ends extending through and being secured to the levers 9.

Each actuating lever 9 is coordinated with one of the cam disks of th stack 6, in such a manner that the inner arms 9:: of the levers acting as feelers or cam followers are normally positioned adjoining to and being displaced axially in the upward direction by a distance equal to the thickness of the coordinated cam disk T he control impulses applied by the disks 6 to the levers 9 in the operative position, FIG. 2, are, in turn, transmitted to the ring 5 by way of a plurality of actuating elements, such as pins 16, projecting from said ring, the arrangement being such that the opposite or outer arms 9b of the lovers 9 in the operative position are urged against the pins 113 by the action of the spring 3, to result in the trans mission olf oscillating movement from cams 6 to the ring rocker members i, and, in turn, to the arm or link 4'. The height of the pins it} varies progressively in such a manner that in the normal or inoperative position of the device, FIG. 1, the arms 9b of the lovers 9 are disen aged from and at least partly overlie the upper ends or" the pins in this position, the levers are furthermore rotativcly urged against stationary stops 11 by the action of the springs 8, to maintain the feelers )a in disengaged position from the surfaces of the cams 6.

The stack of cam disks 6 is mounted upon a shaft 60 projecting beyond the upper end of the stack. Rotativcly mounted upon the projecting end of said shaft is a control knob 12 to which is secured, by the aid of pins 13:: or the l e, a star-shaped piece or cam disk 13, said knob being provided with an internal projection or control cam 14.

The control knob 12 is secured against axial displacement by means of lugs 15a of a pair of supports or bearing blocks 15 mounted upon the base or plate 1. The blocks 15 are furthermore each provided with a recess 15b adapted to receive the outer part of a fixedly mounted ring 16 being secured to said blocks against radial dis placement by means of set screws 150, or in any other suitable manner.

The ring 16 serves as a guide for the bolts 7, being for this purpose provided with suitable perforations through which project the upper ends 7a of the pins for cooperation with the cam or projection 1-! of the control knob 12, as described in further detail hereafter. Besides, the ring 16 serves as support for a pair of double-arm dcl-ecting levers 18, 2, arranged for cooperation with the cam disk 13, on the one hand, and engaging two further bolts 17 secured to the ring 5 and projecting laterally of and beyond the ring 16, on the other hunt. Finally, the ring 16 serves as a support for the stops 11 described previously and corresponding in number to the number of actuating or follower levers 9.

The operation of the device shown will now be described in the following. in order to select a desired pattern or control cam 6, the knob 12 is rotated until its cam or projection 14 engages the end 7a of the bolt 7, coordinated with the desired disk 6, or stitching pattern being selected. As a consequence thereof and due to a slight forward rotation of the disk 6 by the action of the cam disk 13, levers 18 and bolts 17, whereby to more the lever arms 9a out of the way of: the pins 7, the depressed pin together with its coordinated lever 9 will be displaced in the downward direction against the action of the spring 3 and to a distance equal to the height of the projection 14, that is, equal to the thickness of the coordinated disk 6, or of one of the disks 6 if the latter are all of the same thickness. At the some time, the end of. the feeler arm 9a of the lover 9 is operated into enga ement with the surface of the respective cam disk 6, while the opposite lever arm 9b engages its coordinated actuating pin as shown in FIG. 2 if the stack 6 is now rotated, the contour variations of the selected cam will be converted into oscillations of the lever 9 one, in turn, of the ring 5 through which they are transmitted to the needle bar, work feed dog, or the like stitch-controlling organ of the sewing machine, to result in the production of a desired zigzag stitching pattern or design.

As pointed out, in the normal or rest position of the device, FIG. 1, the follower levers 9 are rotatively urged by the action of the springs in such a manner as to retract the follower arms 9a from the cam assembly 6 to an extent until the ends 9b of the levers engage the coordinated stops ill and overlie the upper ends of the belts it). As a consequence, it will not be possible in this position to select any pattern disk by depressing a correspond ing pin 7 directly or by means of the cam 14. In order to effect a selection, it is necessary, as pointed out, to move the bolts it} out of the way of the lever arms 9b, which operation is performed automatically, during the initial movement of the knob, by the cam disk 13, levers 1S and bolts d7, all being suitable structurally related with each other and the remaining parts, in the manner shown in and readily understood from the drawing. More specifically, rotation of the knob 12 causes the radial arms oi the cam piece 13 to engage the bolts 17 of the ring 5, whereby to temporarily rotate the latter and to thereby free the pins 7 from the actuating levers 9, in such a manner as to enable the selected pin 7 to be depressed by the projection 14, as described and understood from the fore going.

The same operation takes place with any of the other follower levers for the selection of the remaining stitching patterns being stored in the cam assembly '6, that is, six patterns or controls involving the provision of six follower levers 9 and six actuating pins 7, according to the example illustrated by FIGS. 1 to 3. For quick identification of the pattern being selected, the knob 12 may be provided with an index cooperating with suitable stationary scale means, in a manner readily understood.

FIG. 4 illustrates an alternative construction of the motion-transmitting rocking member according to which the ring 5 is divided into two equal parts or segments 5:: having radial transmitting arms 4a.. This makes it possible to provide a pair of oscillating drives being controlled by a single cam assembly either independently or simultaneously, such, for example, for the control of the overstitch width and of the work feed, respectively. For the latter purpose, the control knob 12 may be provided with a pair of diametrically positioned cams 14, to afford a simultaneous selection of three combinations of both said controls, or alternatively, a single projection 14 may be provided as in the case of FIG. 3, to afford an independent selection of the disks or cams, as will be understood.

FIG. 5 shows another modification embodying a ring 5 of the rocking member consisting of three equal segments 5a, wherein the cams 14" may be located at the corners of a equilateral triangle, such for example for the simultaneous control of the overstitch width, the stitching position and the work feed, respectively. Alternatively, in order to afford a selective operation of combinations each comprising two of said controls, two additional cams 14' may be provided as in FIG. 4, with or without the further cam 14 of FIG. 3 for the separate or independent selection of the three controls or operations.

in general, where the annular part of the rocking member is composed of plural segments, as shown by FIGS. 4- and 5, to operate different control organs of the sewing machine, the number of control cams of the knob 12, to afford a selection of any of the possible combinations, is determined by the number three multiplied by the number of ring segments minus one, that is, in the case two segments, FIG. 4, there are required control cams, two of which may be located diametrically opposite one another as shown. Thus, in the case of 6: six cam disks 6, as shown in the drawing, three selections of combinations comprising two variables each, such as the overstitch width and work feed, are possible with a control device of this type. The third cam may serve for the independent selection of the cam disks in the manner pointed out in the foregoing.

In the case of a three-segment rocker member or ring, FIG. 5, the number of cams, to enable all possible combinations, is 3 (3 -1)=6 cams. Of the latter, three cams 14" may be located at the corners of an equilateral triangle as shown, whereby, in the case of six cam disks 6, to provide the possibility of effecting two selections of three controls each, such as the overstitch width, stitching position and work feed stroke. in addition, two further diametrically opposed earns 14' may be provided to afford three selections of combinations of two controls each, while again an additional cam 14 may serve for the individual selection of any of the separate controls, in the same manner described hereinbefore.

In the foregoing the invention has been described with reference to a specific illustrative device. It will be evident, however, that variations and modifications, as well as the substitution of equivalent elements and parts for those shown herein for illustration, may be made in accordance with the broader scope and spirit of the invention, as set forth in the appended claims. The specification and drawings are accordingly to be regarded in an illustrative rather than in a restrictive sense.

We claim:

1. A stitching pattern selector assembly for zigzag sewing machines comprising a stack of cam disks mounted for rotation about a common axis, each said disks presenting a different cam surface and each said surfaces corresponding to a predetermined stitching pattern, a motion-transmitting rocking member having a first part forming a ring concentric with and encircling said stack and mounted for rotative oscillatory movement about said axis and a second part radially extending from said rin and adapted for operative connection with an oscillating stitch-forming organ for the production of zigzag stitches by said machine, a plurality of double-arm actuating levers equal in number to and each coordinated with one of said disks, said levers being arranged between said stack and said ring and having pivot axes parallel to and equally spaced from said first axis, one arm of each said levers forming a feeler for cooperation with one of said cam disks and each of the opposite arms of said levers adapted to operatively engage said ring, to transmit oscillating motion thereto in accordance with the surfaces of said disks, and control mechanism to selectively establish motion-transmitting connection between any of said cam disks and said member by way of the respective actuating levers.

2. A stitching pattern selector assembly as claimed in claim 1, said levers being progressively spaced from each other axially by distances corresponding to the thickness of the coordinated cam disks and said feelers and opposite lever arms being normally disengaged from the coordinated disks and said ring, respectively, and means forming part of said control mechanism to selectively engage said disks with their respective feelers and to simultaneously engage the respective opposite lever arms with said ring.

3. A stitching pattern selector assembly as claimed in claim 2, said levers being further axially displaced in one direction relative to their coordinated cam disks by a distance equal to the thickness of the coordinated disks, and further means forming part of said control mechanism to axially displace said levers for simultaneous engagement with the coordinated disks and with said ring, respectively.

4. A stitching pattern selector assembly for Zigzag sewing machines comprising a stack of cam disks mounted lor rotation about a common axis, each said disk presenting a different cam surface and each said surfaces corresponding to a predetermined stitching pattern, a motiontransmitting rocking member having a first part forming a flat ring concentric with and encircling said stack and mounted for rotative oscillatory movement about said axis and a second part radially extending from said ring and adapted for operative connection with an oscillating stitchforming organ for the production of zigzag stitches by said machine, a. plurality of nngularly spaced actuating elements extending transversely from said ring to progressively increasing heights differing from each other by distances equal to the thickness of said disks, a plurality of double-arm follower levers equal in number to and each coordinated with one of said disks, said levers being mounted between said stack and said ring and having pivot axes parallel to and equally spaced from said first axis, and said levers being progressively axially spaced by distances equal to the thickness of the coordinated cam disks with one arm of each lever adapted to form a feeler for cooperation with the coordinated cam disk and with the opposite arm of said levers adapted to engage one of said actuating elements, to transmit oscillatory motion from said disks to said member, and control mechanism to selectively establish motion-transmitting connection between each said disks and said member by way of the respective follower levers and actuating elements.

5. A stitching pattern selector assembly as claimed in claim 4, said levers being normally axially displaced relative to their coordinated cam disks by a distance equal to the thickness of said disks, and means forming part of said mechanism to axially displace said levers for engagement of said feelers with the coordinated disks.

6. A stitching pattern selector assembly for zigzag sewing machines comprising a support plate, a stack of cam disks mounted upon said plate for rotation about an axis transverse to said plate, each said disks presenting a different cam surface and each of said surfaces corresponding to a predetermined stitch pattern, a motion-transmitting rocking member having a first part forming a flat ring mounted for rotative oscillatory movement in a corresponding groove of said plate concentric with said axis and a radial extension of said ring adapted for operative connection with an oscillating stitch-forming organ for the production of zigzag stitches by said machine, a plurality of angularly spaced actuating pins extending transversely from said ring to progressively increasing heights differing from each other by a distance equal to the thickness of the coordinated cam disks, a plurality of doublearm follower levers equal in number and each coordinated to one of said disks, said levers being mounted upon said plate between said stack and said ring and having pivot axes parallel to and equally spaced from said first axis, and said levers being progressively axially spaced by distances equal to the thickness of the coordinated disks and each having a first arm forming a feeler adapted for cooperation with the coordinated disk and a second arm adapted to engage one of said pins, and control mechanism to selectively establish motion-transmitting connection between each said disks and said member by way of the respective actuating pins and follower levers.

7. A stitching pattern selector assembly as claimed in claim 6, means to normally urge said levers to a position of disengagement of said feelers from said disks and of said second arms from said pins, and operating means forming part of said mechanism to establish operative engagement of said levers with the respective cam disks and actuating pins.

8. A stitching pattern selector assembly as claimed in claim 7, said levers being normally displaced relative to their coordinated cam disks by a distance equal to the thickness thereof, and means forming part of said mechanism to effect engagement with the coordinated pins and disks by axial displacement of said levers.

9. A stitching pattern selector assembly as claimed in claim 8, said second lever arms normally overlying said pins, and further means forming part of said control mec ianism to initially rotate said ring prior to the axial displacement of said levers and operative engagement with said pins.

l0. A stitching pattern selector assembly for zigzag sewing machines comprising a stack of cam disks mounted for rotation about a common ans, each said disks presenting a d rent can] surface and each said surfaces corresponding to a predetermined stitching pattern, a motiontransmiiring rocking member having a first part forming at least a segment of a circular ring and mounted for rotative oscillatory movement concentrically with said axis, and a second part radially extending from said first part and adapted for operative connection with an oscillating forming organ for the production of zigzag stitches by said machine, a plurality of double-arm follower levers each being coordinated for cooperation with one or" said disks. said levers being mounted between said stack and said first part and having pivot axes parallel to and equally spaced from said first axis, one arm of said levers forming a feeler for cooperation with one of said disks and each of the opposite arms of said levers adapted to operatively engage said first part, to impart oscillating movethereto from said disks, and control mechanism to selectively establish motion-transmitting connection between each said disks and said member by way of the respective actuating levers.

11. A stitching pattern selector assembly as claimed in claim 10, including at least one further rocking member similar to said first member and forming another seg ment of said ring, and additional follower levers for cooperation with said further rocking member, to control the same by predetermined disks of said stack, whereby to provide a plurality of oscillating drives derived from said stack of control disks for the control of different oscillatin organs of said machine, respectively.

References Cited in the file of this patent UNITED STATES PATENTS 3,653,2 6 Grunke Sept. ll, 1962 

1. A STITCHING PATTERN SELECTOR ASSEMBLY FOR ZIGZAG SEWING MACHINES COMPRISING A STACK OF CAM DISKS MOUNTED FOR ROTATION ABOUT A COMMON AXIS, EACH SAID DISKS PRESENTING A DIFFERENT CAM SURFACE AND EACH SAID SURFACES CORRESPONDING TO A PREDETERMINED STITCHING PATTERN, A MOTION-TRANSMITTING ROCKING MEMBER HAVING A FIRST PART FORMING A RING CONCENTRIC WITH AND ENCIRCLING SAID STACK AND MOUNTED FOR ROTATIVE OSCILLATORY MOVEMENT ABOUT SAID AXIS AND A SECOND PART RADIALLY EXTENDING FROM SAID RING AND ADAPTED FOR OPERATIVE CONNECTION WITH AN OSCILLATING STITCH-FORMING ORGAN FOR THE PRODUCTION OF ZIGZAG STITCHES BY SAID MACHINE, A PLURALITY OF DOUBLE-ARM ACTUATING LEVERS EQUAL IN NUMBER TO AND EACH COORDINATED WITH ONE OF SAID DISKS, SAID LEVERS BEING ARRANGED BETWEEN SAID STACK AND SAID RING AND HAVING PIVOT AXES PARALLEL TO AND EQUALLY SPACED FROM SAID FIRST AXIS, ONE ARM OF EACH SAID LEVERS FORMING A FEELER FOR COOPERATION WITH ONE OF SAID CAM DISKS AND EACH OF THE OPPOSITE ARMS OF SAID LEVERS ADAPTED TO OPERATIVELY ENGAGE SAID RING, TO TRANSMIT OSCILLATING MOTION THERETO IN ACCORDANCE WITH THE SURFACES OF SAID DISKS, AND CONTROL MECHANISM TO SELECTIVELY ESTABLISH MOTION-TRANSMITTING CONNECTION BETWEEN ANY OF SAID CAM DISKS AND SAID MEMBER BY WAY OF THE RESPECTIVE ACTUATING LEVERS. 